The purpose of the research envisioned by this proposal is to prove at least three new concepts in scintillation camera design leading ultimately to the production of high performance whole-body PET cameras which will be more cost effective than any of the positron annihilation radiation imaging systems currently in use. Innovations comprise the development of methods to enable essentially continuous sampling by annular NaI(Tl) scintillation crystal detectors and methods for determining the radial depth of interaction of incident gamma rays in the detector. By incorporating both advances into the design of annular PET cameras we expect to obtain sensitivities 92% higher than are currently possible using NaI(Tl) scintillators and spatial resolution matching state of the art PET systems. The PET cameras, to be developed during Phase II, will be designed primarily for whole-body cancer detection and imaging using Fluorine-18 labeled Fluorodeoxyglucose (FDG), an application shown to be clinically efficacious and cost effective when employing PET systems. It is estimated that the market price of the PET cameras constructed by the methods of this proposal will be about 20 percent higher than that of the of current dual-headed coincidence detection (CD) cameras, which have not been shown to be cost effective primarily because of their poorer sensitivity, and about half the price of current PET cameras. PROPOSED COMMERCIAL APPLICATIONS: This research is expected to make available dependable annular PET cameras having Fluorine-18 fluordeoxyglucose (FDG) imaging characteristics as good as their more expensive counterparts at about half the price. This favorable cost/benefit ratio should result in a strong market acceptance.